Older versions of our server monitoring documentation still mention ismaster. This should be changed to "legacy hello". And buildinfo should be buildInfo. For example:

https://mongodb.github.io/mongo-csharp-driver/2.12/reference/driver_core/

The 2.15, 2.16, and 2.17 (as well as $/Docs/) still mention buildinfo, but 2.15 switched over to maxWireVersion for feature detection. We should correct this too.